This invention relates to a spectrophotometer for detecting components of a sample inside a cell by exposing it to light, and more particularly to such a spectrophotometer having validation programs therefor stored in a memory corresponding to the kind of cell used for the testing. Such a spectrophotometer may be used either singly or as a detector, for example, for a liquid chromatograph.
When a spectrophotometer is used as a detector for a liquid chromatograph, its cell is irradiated with light as a sample separated in the column passes through it together with a solvent, and the concentrations of its components are quantitatively analyzed by measuring the absorptivity and the coefficient of refraction of this light. Many different kinds of cells are available such as standard cells, micro-cells with a small inner diameter, high-pressure cells with a high resistance against high pressures and fractioning cells having a shorter optical path, which may be used selectively, depending on the purpose and/or conditions of the analysis.
Prior to an analysis, the spectrophotometer is sometimes made to undergo so-called validation tests, say, for a measurement of drift noise, a wavelength correction and a determination of accuracy in light measurements. In such a case, the user is usually required to select software and hardware from a menu. This has been a cumbersome procedure.
It is therefore an object of this invention to provide an improved spectrophotometer on which various validation processes can be carried out without any cumbersome procedure.
A spectrophotometer embodying this invention, with which the above and other objects can be accomplished, may be characterized as comprising not only an optical system for irradiating a cell with an incident beam of light having a specified wavelength, a detector for detecting light received from the cell and a data processor for precessing data based on detection signals from the detector, but also a cell sensor and a cell identifier for detecting whether a cell is mounted and, if so, the kind of the mounted cell, a program memory which stores validation programs for carrying out validation tests and a validation controller for retrieving from the program memory one of the stored validation programs corresponding to the identified kind of the cell and carrying out the retrieved validation program. It is thus adapted to have any of a plurality of validation cells mounted thereto and to automatically start a validation process associated with the kind of the validation cell which is mounted.